With time the list of connected Bluetooth devices accumulates on your Samsung Galaxy S7. Many of the connected Bluetooth device you may not use, so you want to remove them from the list.
If so, then you can clean up the Bluetooth device list on the Samsung Galaxy S7 as follows.
Open the following submenu:
Home Screen --> apps menu --> Settings --> Bluetooth
You will see here the list of paired devices. In order to remove a no longer used device from the list, tap the gear icon and then in the next sub-menu to "decoupling".
The Bluetooth device disappears now on your Samsung Galaxy S7 from the list of paired devices. You now know how to decouple a Bluetooth device related to the Samsung Galaxy S7.